Take the Driver's Seat on Sea Level Science

A new NASA
sea level simulator lets
you bury Alaska's Columbia glacier in snow, and, year by year, watch how it
responds. Or you can melt the Greenland and Antarctic ice sheets and trace
rising seas as they inundate the Florida coast.

Computer models
are critical tools for understanding the future of a changing planet, including
melting ice, rising seas and shifting precipitation patterns. But typically,
these mathematical representations -- long chains of computer code giving rise
to images of dynamic change -- are accessible mainly to scientists.

The new simulator,
however, allows anyone with a computer to perform idealized experiments with
sea level and learn about its complexities. Developed by scientists at NASA's
Jet Propulsion Laboratory in Pasadena, California, the interactive platform,
called the Virtual Earth System Laboratory (VESL), provides the public with a
taste of how NASA models important Earth processes.

The platform will
also prove useful to scientists as a convenient way to create visual
representations of data.

While many
interface tools are available to explore sea level effects, VESL stands apart
for its strong representation of Earth's cryosphere - the melting ice caps, ice
sheets and glaciers that are major contributors to sea level rise.

And the
simulator is not just a simplified version of a model or a menu of preexisting
results. It is direct access to the complex, number-crunching model itself,
though with limited scenarios and factors that can be adjusted.

"It's the real
software, being used on the fly, live, without being prerecorded or
precomputed," said Eric Larour of JPL, who led VESL's development. "You have
access to a segment of an ice sheet model or sea level model, running NASA's
software."

Despite these
capabilities, VESL won't overtax computers.

"A key to
making the interface tool work is cloud computing," Larour said. Instead of
burdening your own computer with heavy demand, "you can access a JPL cloud to
run big simulations."

The VESL
platform allows the user to control one or two parameters for each model
scenario. For example, in a version of the model configured to represent
Columbia Glacier, a slider allows users to change snowfall amounts and examine how
the change affects the glacier's behavior in subsequent years. For a sea level simulation,
sliders control the rates at which the ice sheets on Antarctica and Greenland
are melting.

"You can
explore different aspects of the model that maybe even the scientists didn't
explore," Larour said.

The site will
be updated frequently to keep up with the latest, peer-reviewed research. Scientists
will eventually be able to use the graphical interface to display and present
new data sets or model results, while lay users will be able to replicate
published research results for themselves using models that are "open source,"
or publicly available.

"As we make
progress, [the public] can rerun the science that we actually do," Larour said.
"If anybody has concerns or finds issues with our simulation, they have the
ability to replicate our results. We would welcome feedback and inputs to
improve our science."

VESL was developed
over five years by members of the Ice Sheet System Model development team at JPL
and the University of California, Irvine (UCI), with the help of several
students, including Dan Cheng from UCI and Gilberto Perez, who attended both Cal
Poly Pomona and UCI.

The website
hosting the simulator will also include a public outreach section, being
developed by Daria Halkides, a scientist and outreach exhibit developer of
Earth & Space Research in Seattle and a JPL affiliate.

"VESL was initially
intended for scientists," Larour said. "Then we realized it could also be an
excellent tool for public outreach. These simulations are so easy to run, and
visually so compelling, that any person from the public can go and run them and
probably understand what is going on."

A paper
describing the development of the ice sheet simulator, titled "A JavaScript API for the Ice Sheet System Model: Towards on
online interactive model for the Cryosphere Community," appears today in
the journal Geoscientific Model Development.

A paper describing the development of the ice sheet simulator appears today in the journal Geoscientific Model Development.